1. Field of the Invention
This invention relates to improvements in apparatus for continuously making rigid foam plastic insulating panels for use in building construction.
2. Description of the Prior Art and Objects
It is known to provide configured belts backed up by rigid conveyors for the continuous molding of three dimensional material as shown in U.S. Pat. No. 3,914,084. More and more materials for the building and general construction industry such as siding, insulating siding sheets and panels are being made out of polystyrene, cellulose acetate, polyurethane and the like thus necessitating the construction of more machines to supply this demand. However, due to the high pressures encountered during the continuous molding of such material out of the aforementioned plastic foams, the machines to make such material are very expensive to manufacture, operate and maintain. The major expense areas are in the complex controls and gearing to drive the parallel belt carrying conveyors, devices to set initial pressure between the configured belts, extensive stationary tracking to maintain the configured belts together during the foam reaction, the configured belts themselves, and the parallel conveyors, particularly if they consist of a series of articulated platens.
In addition to the cost of the machines of the prior art as aforementioned, there is often enormous waste of material resulting from their operation due to the leakage from the mold of the foam core as it expands thus necessitating extensive trimming to achieve the final product.
The primary object of the present invention is thus to provide a novel apparatus for the continuous production of rigid foam plastic insulating paneling which overcomes all of the previously mentioned objections of the apparatus of the prior art.
It is another object of the present invention to provide such an apparatus employing conveyor bands consisting of a series of interlocked, articulated platens of extruded metal having a finned surface for heat absorption and dissipation.
It is yet another object of the present invention to provide such an apparatus employing belts of castable plastic material, the upper and lower sections of the belt forming a continuous mold cavity and each section having continuous mating grooves and projections for containing the expanding foam.
It is a further object of the present invention to provide such an apparatus having resilient metal clips for maintaining the bands and thus belts in precise relationship to each other.
It is a still further object of the present invention to provide such an apparatus utilizing conventional tires as support and drive rollers for the conveyor bands and the degree of inflation thereof controlling the pressure exerted on the belts by the conveyor bands.
The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objectives and advantages thereof will be better understood from the following description considered in connection with the accompanying drawing in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawing is for the purpose of illustration and description only, and is not intended as a definition of the limits of the invention.